[tracing] Move and rename TRACE_EVENT_API_TASK_EXECUTION_EVENT

base/trace_event/heap_profiler.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef BASE_TRACE_EVENT_HEAP_PROFILER_H
 #define BASE_TRACE_EVENT_HEAP_PROFILER_H
 
 #include "base/compiler_specific.h"
 #include "base/trace_event/heap_profiler_allocation_context_tracker.h"
 
 // This header file defines the set of macros that are used to track memory
 // usage in the heap profiler. This is in addition to the macros defined in
 // trace_event.h and are specific to heap profiler. This file also defines
 // implementation details of these macros.
 
 // Implementation detail: heap profiler macros create temporary variables to
 // keep instrumentation overhead low. These macros give each temporary variable
 // a unique name based on the line number to prevent name collisions.
 #define INTERNAL_HEAP_PROFILER_UID3(a, b) heap_profiler_unique_##a##b
 #define INTERNAL_HEAP_PROFILER_UID2(a, b) INTERNAL_HEAP_PROFILER_UID3(a, b)
 #define INTERNAL_HEAP_PROFILER_UID(name_prefix) \
   INTERNAL_HEAP_PROFILER_UID2(name_prefix, __LINE__)
 
+// Scoped tracker for task execution context in the heap profiler.
+#define HEAP_PROFILER_API_SCOPED_TASK_EXECUTION_EVENT \
+  trace_event_internal::HeapProfilerScopedTaskExecutionEvent
+
 // A scoped ignore event used to tell heap profiler to ignore all the
 // allocations in the scope. It is useful to exclude allocations made for
 // tracing from the heap profiler dumps.
 #define HEAP_PROFILER_SCOPED_IGNORE                                          \
   trace_event_internal::HeapProfilerScopedIgnore INTERNAL_HEAP_PROFILER_UID( \
       scoped_ignore)
 
 namespace trace_event_internal {
 
+// HeapProfilerScopedTaskExecutionEvent records the current task's context in
+// the heap profiler.
+class HeapProfilerScopedTaskExecutionEvent {
+ public:
+  inline explicit HeapProfilerScopedTaskExecutionEvent(const char* task_context)
+      : context_(task_context) {
+    if (UNLIKELY(
+            base::trace_event::AllocationContextTracker::capture_enabled())) {
+      base::trace_event::AllocationContextTracker::GetInstanceForCurrentThread()
+          ->PushCurrentTaskContext(context_);
+    }
+  }
+
+  inline ~HeapProfilerScopedTaskExecutionEvent() {
+    if (UNLIKELY(
+            base::trace_event::AllocationContextTracker::capture_enabled())) {
+      base::trace_event::AllocationContextTracker::GetInstanceForCurrentThread()
+          ->PopCurrentTaskContext(context_);
+    }
+  }
+
+ private:
+  const char* context_;
+};
+
 class BASE_EXPORT HeapProfilerScopedIgnore {
  public:
   inline HeapProfilerScopedIgnore() {
     if (UNLIKELY(
             base::trace_event::AllocationContextTracker::capture_enabled())) {
       base::trace_event::AllocationContextTracker::GetInstanceForCurrentThread()
           ->begin_ignore_scope();
     }
   }
   inline ~HeapProfilerScopedIgnore() {
     if (UNLIKELY(
             base::trace_event::AllocationContextTracker::capture_enabled())) {
       base::trace_event::AllocationContextTracker::GetInstanceForCurrentThread()
           ->end_ignore_scope();
     }
   }
 };
 
 }  // namespace trace_event_internal
 
 #endif  // BASE_TRACE_EVENT_HEAP_PROFILER_H